build.sh: Add extra git debug output

Only when CI_DEBUG_BUILD is non-empty
7 jobs for no-clone-complete-repo in 1 minute and 33 seconds
Status Job ID Name Coverage
  Verify
passed #44584
x86_64 docker-alpine
lint

00:00:26

 
  Build
passed #44589
aarch64 ci-docker-image docker-alpine
build-aarch64

00:00:24

passed #44590
armv7 ci-docker-image docker-alpine
build-armv7

00:00:25

passed #44588
ppc64le ci-docker-image docker-alpine
build-ppc64le

00:00:32

passed #44585
s390x ci-docker-image docker-alpine
build-s390x

00:00:38

passed #44587
x86 ci-docker-image docker-alpine
build-x86

00:00:23

passed #44586
x86_64 ci-docker-image docker-alpine
build-x86_64

00:00:26